The present invention relates generally to medical devices and methods. More particularly, the present invention relates to devices and methods for the magnetic attachment of expandable devices and the like within a patient""s body cavity, such as the stomach, intestine or gastrointestinal tract.
In cases of severe obesity, patients may undergo several types of surgery either to tie off or staple portions of the large or small intestine or stomach, and/or to bypass portions of the same to reduce the amount of food desired by the patient, and the amount absorbed by the intestinal tract. Procedures such as laparoscopic banding, where a device is used to xe2x80x9ctie offxe2x80x9d or constrict a portion of the stomach, or placement of intragastric balloons, can achieve these results.
Endoscopic procedures that have been used to assist weight loss have primarily focused on placement of a balloon or other space-occupying device in the patient""s stomach. This fills portions of the stomach and provides the patient with a feeling of fullness, thereby reducing food intake. To accomplish these procedures, an endoscope is utilized to guide the balloon through the patient""s mouth and down the esophagus to the stomach. Usually these procedures have allowed placement of the device for 3-6 months, and are coupled with counseling and other types of behavioral modification programs.
Many of the conventional surgical interventions require the patient to submit to an intervention under general anesthesia, and can require large incisions and lengthy recovery time. The less invasive procedures, although clinically efficacious in many cases, suffer from complications ranging from deflation of the devices to insufficient anchoring of these devices resulting in unsustained weight loss, stomach erosion, bowel obstruction and even death.
Many of these devices are neither robust enough nor are they adequately secured within the stomach to sustain long term implantation. As a result, many implanted devices are implanted in such a manner as to remain unattached or free-floating within the stomach. Further, due to the caustic nature of stomach acids and other factors, many of the implants deflate and migrate into the intestine, causing bowel obstructions and in some cases death. Also, many devices are not well designed for removal, leading to additional technical difficulties for the clinician.
The present invention provides improved methods and apparatus for implanting and anchoring space-occupying devices into the gastrointestinal system of a patient, e.g., the stomach of the patient, which can be deployed in a minimally invasive manner such as transesophageal endoscopy. The invention allows greater access to procedures and devices by patients who might not otherwise be treated surgically as xe2x80x9cmorbidly obesexe2x80x9d (at or above a Body Mass Index (BMI) of 40 kg/m3), but who may just be moderately obese or overweight (BMI of between 25 to 40 kg/m3). In addition, patients who require more invasive surgery for an unrelated ailment, may need a minimally invasive way to lose the weight prior to their more invasive procedure, thereby reducing the risks associated with general anesthesia, or otherwise enabling the more invasive procedure.
Expandable devices that may be inserted into the stomach of a patient may be maintained within the stomach by anchoring or otherwise fixing the device to the stomach wall of the patient. Such expandable devices, e.g., an inflatable balloon, may comprise two portions, an inner portion and an outer portion, the inner portion being able to maintain its shape, regardless of the integrity of the outer portion. Other expandable balloon devices may be used to maintain their expanded shape and desired volume, independent of any small leaks that may develop over time, or they may be configured to maintain a volume of the space-occupying device that can be adjusted in-situ, to change the size of the device after implantation.
The space-occupying devices may be anchored to the stomach wall by an anchoring device that may comprise one or more proximal magnetic devices for magnetically coupling with a distal magnetic anchor located on the stomach wall. The magnetic device and anchor may both be magnets or portions of magnetizable material. Similarly, the proximal magnetic device may be a magnet or portion of magnetizable material while the distal magnetic anchor may be a magnet of opposite polarity, or a magnetically attractive metal. Alternatively, the proximal device may be a magnetically attractive metal and the distal anchor may be a magnet.
The magnetic device may be affixed to the space-occupying member, or may be movable within the member and directable to the site of attachment at the stomach wall by magnetic attraction. The magnetic device may be completely within the space-occupying member. On the other hand, the magnetic device may be positioned on an external surface of the space-occupying member or be integral thereto, and be configured such that a portion of it extends at least partially through one or several folds of the patient""s stomach wall, thereby maintaining the device within the patient""s stomach.
As will soon become apparent, the magnetic device and anchor may take any variety of configurations and be made of any number of materials. Similarly, the device and anchor may have a variety of different surfaces. They may be textured, or have a detent. In this way, adequate perfusion of tissue is accomplished and ischemic tissue necrosis is prevented. Any number of coupling devices may be used.